Posted by www.poolplantcourses.org on Monday, January 23, 2012 Under: Videos
Energy is used when increasing the temperature of something. Heat is transferred from something hot to something cool.This heat is called 'sensible heat'. Energy is also used when a change takes place in the state of something. For example, when liquid water turns into water vapour.
Both of these forms of heat are used to achieve energy efficiencies in some air handling systems for swimming pool halls. In order to provide a healthy and comfortable environment for bathers, spectators and staff, it is necessary to introduce fresh air into the building. Continually recirculating the air would lead to poor environmental conditions. In order to make way for the incoming fresh air, some of the air already in the pool hall will need to be expelled. The fresh air will need heating and it is possible to obtain some of the energy necessary for this from the outgoing air, which is hot and contains much more moisture than the incoming air (at least in the UK anyway).
What you may find surprising is that both the sensible heat (the difference in temperature) AND the latent heat (the difference in state, ie, liquid to water vapour) can be transferred. The video below provides a good explanation and demonstration as to how this happens. It demonstrates how energy is released when water turns to ice, but the priciples are the same when water vapour (in the outgoing air) is turned into water (as it condenses onto the condensing coil in the air handling system).
